The town's name is taken from one of the three villages it surrounded (the other two being Willian and Norton) – all of which featured in the Domesday Book.The land used was purchased by Quakers who had intended to farm the area and build a Quaker community.The Spirella Building, completed in 1920, blends in despite its central position through being disguised as a large country house, complete with towers and a ballroom.During the Second World War, the factory was also involved in producing parachutes and decoding machinery.According to the book the term "Garden City" derived from the image of a city being situated within a belt of open countryside (which would contribute significantly to food production for the population), and not, as is commonly cited, to a principle that every house in the city should have a garden.The concept outlined in the book is not simply one of urban planning, but also included a system of community management.
Blackhorse Road was built on what was the continuation of the original Icknield Way.
Because corsets fell out of fashion, the factory closed in the 1980s, and was eventually refurbished and converted into offices.
Another significant employer in the town was Shelvoke and Drewry, a manufacturer of dustcarts and fire engines which existed from 1922 until 1990; as was Hands (Letchworth), James Drewry joining them in 1935, who manufactured axles, brakes and Hands Trailers.
Letchworth had a very diverse light industry, including K & L Steel Foundry, often a target for German bombers in World War II, the Letchworth Parachute Factory, J. Dent and Son (also known as The Aldine Press, Garden City Press).
The biggest employer was British Tabulating Machine Company, later merging with Powers-Samas to become International Computers and Tabulators (ICT) and finally part of International Computers Limited (ICL).